An Asian elephant eats a pine tree in her enclosure at Berlin's Zoologischer Garten zoo, on Jan. 13. The elephants are fed pine trees discarded by Berlin residents after Christmas, once a year.

Caroline Seidel / EPA

An elephant holds up a fir tree at the Zoo in Berlin, Germany, on Jan. 13. Every year, the elephants of the Berlin Zoo receive Christmas trees that were not sold during the holiday season. Firs and spruces are a great supplement to the nutritional protocol of the animals.

It turns out that Christmas trees are tasty snacks for elephants. Each year, German zoos will feed unsold Christmas trees to their elephants. The trees are donated by the tree sellers, who would otherwise throw them away. Germany's Spiegel Online spoke to Thomas Kauffels, director of the Opel Zoo near Frankfurt:

Elephants like to eat wood, it's important for their digestion because it gives them roughage, especially in winter when there aren't many leaves on the trees. We fed them one or two trees each per day. If we gave them 10 at a time they'd get picky and would only eat the tips.

Our elephants like the trees. I certainly haven't had any complaints.

The elephants pictured certainly seem to enjoy it!

Caroline Seidel / EPA

An elephant eats parts of a fir tree at the Zoo in Berlin, Germany, on Jan. 13. Every year, the elephants of the Berlin Zoo receive Christmas trees that were not sold during the holiday season. Firs and spruces are a great supplement to the nutritional protocol of the animals.